//////////////////////////////////////////////////////////////////////////
//
//  Copyright (c) 2011, John Haddon. All rights reserved.
//  Copyright (c) 2013, Image Engine Design Inc. All rights reserved.
//
//  Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions are
//  met:
//
//      * Redistributions of source code must retain the above
//        copyright notice, this list of conditions and the following
//        disclaimer.
//
//      * Redistributions in binary form must reproduce the above
//        copyright notice, this list of conditions and the following
//        disclaimer in the documentation and/or other materials provided with
//        the distribution.
//
//      * Neither the name of John Haddon nor the names of
//        any other contributors to this software may be used to endorse or
//        promote products derived from this software without specific prior
//        written permission.
//
//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
//  IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
//  THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
//  PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
//  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
//  EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
//  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
//  PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
//  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
//  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
//  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
//////////////////////////////////////////////////////////////////////////

#pragma once

#include "Gaffer/DirtyPropagationScope.h"

#include "IECore/RefCounted.h"

#include <string>

namespace Gaffer
{

IE_CORE_FORWARDDECLARE( ScriptNode );

/// The UndoScope class is used to control the creation of
/// items on the undo stack held in a ScriptNode.
class GAFFER_API UndoScope : DirtyPropagationScope
{

	public :

		enum State
		{
			Invalid,
			Enabled,
			Disabled
		};

		/// Script can be 0, in which case the subsequent actions
		/// will not be undoable regardless of the specified state.
		///
		/// If mergeGroup is specified and matches the group used by
		/// the previous UndoScope, then the actions performed will
		/// be merged with the previous entry on the undo stack. This
		/// can be used by UI elements to compress a series of individual
		/// editing events such as an interactively updated drag into
		/// a single item on the undo stack.
		explicit UndoScope( ScriptNodePtr script, State state=Enabled, const std::string &mergeGroup=std::string() );
		~UndoScope();

	private :

		ScriptNodePtr m_script;

};

} // namespace Gaffer
